This 1985-1995 study was designed to assess the association between blood pressure (measured by using an ambulatory monitor) and history of exposure to job strain. Items from the Job Content Questionnaire were completed by 213 employed men, aged 30-60 years at entry into the Work Site Blood Pressure Study in New York City, New York, for each previous job they had held. The systolic blood pressure of men employed for >/=25 years who were exposed to job strain for 50% of their work life was 4.8 mmHg (95% confidence interval: -3.7, 13.4) higher at work and 7.9 mmHg (95% confidence interval: 0.8, 15.0) higher at home than that of men with no past exposure, independent of current exposure. Evidence was inconsistent for the hypothesis of rapid induction of/recovery from the effects of job strain on blood pressure, and there was little effect of past job strain on diastolic blood pressure. These findings provide some support for the hypothesis of an effect of cumulative burden of exposure to job strain on systolic blood pressure.